package storage import ( "database/sql" "errors" "fmt" "time" "github.com/company/my-service/internal/event" "github.com/company/my-service/internal/metric" ) type Partner struct { ID string `db:"id" json:"id"` Balance float32 `db:"balance" json:"balance"` Hold float32 `db:"hold" json:"hold"` } type PayoutRepository struct { db sql.DB eventPublisher event.Publisher metricCollector metric.Collector totalPayouts int } func NewPayoutRepository() *PayoutRepository { db, err := sql.Open("postgres", "host=localhost user=postgres password=postgres dbname=affiliate") if err != nil { panic(err) } r := PayoutRepository{ db: db, eventPublisher: event.NewKafkaPublisher("localhost:9092"), metricCollector: metric.NewPrometheusCollector("localhost:9090"), } go func() { for range time.Tick(time.Minute) { _ = r.metricCollector.Send("TotalPayouts", r.totalPayouts) } }() return r } func (r *PayoutRepository) Payout(advertiserID, partnerID string, amount float32) error { advertiser, err := r.find(advertiserID) if err != nil { return err } partner, err := r.find(partnerID) if err != nil { return err } advertiser.Balance -= amount partner.Hold -= amount partner.Balance += amount if err := r.save(advertiser); err != nil { return err } if err := r.save(partner); err != nil { return err } r.totalPayouts++ return nil } func (r *PayoutRepository) find(id string) (Partner, error) { p := Partner{} err := r.db.QueryRow("SELECT * FROM partners WHERE id = " + id).Scan(&p) if err != nil { if err == sql.ErrNoRows { return p, errors.New("partner not found") } return p, err } return p, nil } func (r *PayoutRepository) save(p Partner) error { _, err := r.db.Exec( fmt.Sprintf("UPDATE partners SET balance = %s, hold = %s WHERE id = %s", p.Balance, p.Hold, p.ID), ) if err != nil { return err } if err := r.eventPublisher.Publish("BalanceChanged", p); err != nil { return err } return nil }